Gamaxine poisoning treatment
Reading File
Finding Sources
Finding Sources
Searching the Web
gamaxine lindane poisoning treatment management
Reading File
Reading File
I have excellent content from Tintinalli's EM. The Rosen's section was about organophosphates. I have enough from the textbook and web sources to give a comprehensive answer now.
Gamaxine (Lindane / gamma-HCH) Poisoning - Treatment
Gamaxine is a trade/common name for lindane (gamma-hexachlorocyclohexane, gamma-BHC), an organochlorine insecticide also used therapeutically for scabies and head lice. It is a CNS stimulant poison with no specific antidote.
Mechanism of Toxicity
Lindane antagonizes GABA-A receptor-mediated chloride channel inhibition, removing the brain's normal inhibitory tone. This leads to:
- Repetitive neuronal discharges after each action potential
- Neuronal hyperexcitability
- Seizures
It is highly lipid-soluble and accumulates in tissues. It also induces hepatic microsomal enzymes (CYP450), which can reduce efficacy of co-administered drugs.
- Tintinalli's Emergency Medicine, p. 1345
Routes of Exposure
- Ingestion (most serious - well absorbed)
- Inhalation
- Dermal (especially through abraded skin or repeated application; children and elderly are at higher risk from topical therapeutic use)
Clinical Features
Mild Poisoning
- Dizziness, ataxia, fatigue, headache
- Irritability, hyperexcitability, delirium, apprehension
- Tremors, myoclonus
- Facial paresthesias
- Nausea, vomiting
Severe Poisoning
- Seizures (may occur early, without prodrome; status epilepticus possible)
- Hyperthermia
- Coma
- Renal injury
- Cardiac arrhythmias (myocardial sensitization - risk of ventricular fibrillation)
- Respiratory depression/failure
- Death
Note: Lindane is often dissolved in hydrocarbon solvents that can independently cause sedation, coma, and aspiration pneumonitis.
Management
1. Decontamination
| Route | Action |
|---|---|
| Ingestion | Do NOT induce emesis (seizures may occur abruptly). Gastric lavage if early presentation. Give activated charcoal (50g adults, 1g/kg children). Do NOT give milk, fats, or oils - they enhance absorption. |
| Dermal | Remove contaminated clothing. Wash skin thoroughly with soap and water. |
| Eye exposure | Irrigate immediately with water or saline for 15 minutes. |
| Inhalation | Remove from exposure; fresh air immediately. |
2. Seizure Control (Priority #1)
- Benzodiazepines first line: Diazepam (IV 5-10mg, repeat as needed) or lorazepam - act as GABA agonists, directly counteracting the mechanism
- Phenobarbital for refractory seizures (also GABAergic)
- Avoid phenytoin - less effective for toxin-induced seizures
- Treat status epilepticus aggressively
3. Supportive / Cardiorespiratory Care
- Establish IV access (at least one large-bore line)
- Maintain airway; intubate if needed
- Supplemental oxygen; mechanical ventilation if respiratory failure
- Avoid adrenaline (epinephrine) and other adrenergic amines - organochlorines sensitize the myocardium, and catecholamines may precipitate ventricular fibrillation
- Avoid atropine unless there is a specific bradyarrhythmia indication - it can worsen ECG changes
- Cardiac monitoring (continuous ECG)
4. Monitoring
| Parameter | Why |
|---|---|
| CPK (creatine phosphokinase) | Monitor for 24-48h; rhabdomyolysis possible with severe seizures |
| Myoglobin / urinalysis | Myoglobinuria if CPK rises (risk of acute tubular necrosis) |
| Renal function (BUN, creatinine) | Direct renal toxicity + rhabdomyolysis |
| Acid-base status (ABG) | Metabolic acidosis with severe convulsions |
| Blood glucose | Hyperglycemia/hypoglycemia can worsen outcome |
| Blood/serum lindane levels | Confirm exposure; monitor elimination (GLC method) |
5. Enhanced Elimination
- There is no established dialysis benefit (highly lipid-soluble, large volume of distribution)
- Cholestyramine has been tried to interrupt enterohepatic recirculation but evidence is limited
- Maintain hydration and urine output, especially if CPK is elevated (prevents cast nephropathy)
6. No Antidote
There is no specific antidote. All treatment is supportive and symptomatic.
Summary Table
| Problem | Treatment |
|---|---|
| Seizures | Diazepam / lorazepam IV (first line); phenobarbital (refractory) |
| Ingestion decontamination | Activated charcoal; NO emesis; NO milk/fats |
| Skin/eye exposure | Wash skin; irrigate eyes |
| Cardiac sensitization | Avoid epinephrine, adrenergic amines |
| Rhabdomyolysis | IV fluids, monitor CPK + urine |
| Respiratory failure | Intubation, mechanical ventilation |
Sources:
- [Tintinalli's Emergency Medicine, 9th Ed.](p. 1345-1346) - Organochlorines section
- INCHEM PIM 859 - Lindane management guidelines
- PMC case report: Lindane & Cetrimide poisoning management
This is a shared conversation. Sign in to Orris to start your own chat.